Single step pre-swelling and etching of plastics for plating

ABSTRACT

A one-step process for treating polymer surfaces prior to electroless deposition is disclosed. Polymer parts are dipped in a solution containing a good solvent for the polymer, a substantial non-solvent for the polymer, an etchant and, where one of these is immiscible with one or more of the others, a solubilizing agent miscible with the immiscible components to provide a single liquid phase. Formulations are provided for pre-swelling and etching of functionalized polymers, such as polycarbonate in one, two and three steps. The etched surface can then be plated with electroless nickel or copper with satisfactory adhesion of the plated metals. Swelling agents make polymer molecules on and near the surface of the polymer easily accessible to a degradation agent. A degradation agent degradates the polymer molecules. If required, a solubilizing agent increases the miscibility of the degradation agent and the swelling agent. A wetting agent increases the effectiveness of the etching agent.

This application is a division of application Ser. No. 07/268,154, filed11/7/88 now U.S. Pat. No. 4,941,940.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to formulations and processes for swelling,etching and plating for decorative and functional purposes of plasticsof functionalized polymers, suitably those having at least onehydrolyzable functionality such as anhydride, carbonate, ester (carboxyland sulfonic), amide, urethane and imide. The polymer could be acopolymer and/or an alloy of two or more polymers. The invention is ofparticular value withpoly(oxy-carbonyloxy-1,4-phenylene-isopropylidene-1,4-phenylene),referred herein as polycarbonate and/or PC. The etching formulationsutilize at least one swelling agent and at least one degradation agent.The etched surface can be plated with electroless nickel or copper withsatisfactory adhesion of the plated metals.

2. Brief Description of the Prior Art

General Prior Art

General art of etching and plating of plastics, including formulationsand processes is described in a number of books and reviewsincluding: 1. Guidebook Directory, Metals and Plastics Publications,Inc., Hackensack, N.J. 1988; 2. Standards and Guidelines forElectroplated Plastics, American Society of Electroplated Plastics,Englewood Cliffs, N.J. 1984; 3. Metallic Coating of Plastics, W. Goldie,Electrochemical Publication Ltd., Hatch End, England, 1968; and 4.Electroplating of Plastics, I. R. Weiner, Finishing Publications Ltd.,Hampton Hill, England, 1977. Plastic parts are subjected to thefollowing major processes to plate them: pre-swelling (if required),etching, neutralizing, catalyzation, acceleration, electroless platingand electroplating. The details of these processes and formulations aregiven in the above references.

Prior Art for Polycarbonate

Polymeric plastics are plated for decorative and functional reasons suchas decoration and electromagnetic interference (EMI) shielding. In orderto prevent EMI from escaping the source and protect sensitive electronicequipment from outside EMI sources, electronic equipment which cangenerate frequency between 10⁴ to 10⁹ (10,000 to 10 billion) cycles persecond should be shielded. The most widely used plastic for housingelectronic devices is polycarbonate. Polycarbonate is generallyunaffected by aqueous solution of etchants and hence requirespre-swelling. The terms, swelling, pre-swelling, pre-etching,pre-conditioning, and pre-treatment are used interchangeably herein.

Many polymers having hydroxylatable functionalities, such aspolycarbonate have tough surfaces. They cannot be sufficiently etchedwith common aqueous etchants such as aqueous chromic acid or aqueousalkali metal hydroxides. Pre-swelling is required for fast etching. Inparticular, polycarbonate is not soluble in a number of common organicsolvents. The good or "fast" solvents are those in which it is highlysoluble at room temperature. The "poor", "slow" or "minor roughening"solvents are those in which it has limited solubility at roomtemperature. The nonsolvents are those in which it is insoluble.

Good solvents usually cause excessive swelling, hence a surface which isvery rough and unsuitable for subsequent plating. If transparent plasticis used, it becomes essentially opaque. With poor solvents which cause aproper degree of swelling, the surface is uniformly micro-roughened andcan be plated. If transparent plastic is used, it becomes translucent ina poor solvent. This properly swollen surface is required for properetching and plating of plastics. Nonsolvents do not swell the plasticand hence there can be no adhesion for plating. Thus, if a transparentsheet is used, it remains transparent.

Preswollen PC is easy to degrade as the swelling provides a highersurface area and porous surface. As a result, the etching/degradation israpid. The roughened surface also provides a strong mechanical bondingbetween the plastic and the plated metals to be plated thereon.Degradation of PC provides polar functionalities such as --OH and --COOHon the micro-roughened surface which, in turn, provides a wettablesurface. Such a wettable surface is required for electroless plating ofmetals as all commercially available plating baths are aqueous.

One pre-swelling system available commercially, uses toxic halocarbonsolvents for pre-swelling and is frequently followed by chromic acid asan etchant. For example, the pre-swelling system offered by Shipleyinc., (according to the Material Safety Data Sheet of Shipley for PM-921Conditioner) uses dichloropropanol to pre-etch polycarbonate.

There is a need for a nontoxic solvent for pre-etching polycarbonate.There is also a need for a etching system for polycarbonate which isnontoxic and provides excellent adhesion of electroless copper or nickel(at least as good as that obtained with chromic acid). In order toreduce the cost due to drag out and save time, it is desirable toutilize one bath to simultaneously achieve swelling and etching ofpolycarbonate.

As halocarbons can undergo dehydrohalogenation and oxidation, it isdifficult to prepare a stable bath containing a mixture of halocarbon(as pre-etch) with either a strong base etchant or with chromic acidwhich is a strong oxidizing agent. In addition, chromic acid is toxic,expensive, produces a toxic fumes. Furthermore, recovery of chromium andwaste disposal of chromium (sludge) is expensive. While alkali metalhydroxides have been used for etching polycarbonate, they are not veryeffective in providing a surface with satisfactory properties forelectroless plating. The use of mixtures of swelling agents (and/orsolubilizing agents) and degradation agents as etching systems forpolycarbonate has not been reported.

Prior Patents

A number of patents have been issued on swelling, etching, and platingof plastics. Most of these patents relate to etching of ABS (a copolymerof acrylonitrile, butadiene, and styerene) with chromic acid. There areseveral patents on pre-swelling and non-chromic acid etching.

U.S. Pat. No. 3,649,391 describes a process for producing a markingreceptive (pre-swelling/etching) surface of polystyrene by action of asolution of chloromethane, perchloroethylene, and heptane. The claimedformulations can be used for polystyrene only. U.S. Pat. Nos. 3,660,293,3,671,289, 3,795,622 and 4,281,034 describe processes of increasingadhesion of electroless metals by pre-swelling ABS with aqueoussolutions of hydroxylated and etherified monoacetate, e.g., glycoldiacetate and cellusolve acetate; five membered heterocyclic compoundssuch as propylene carbonate and mixture of halocarbons and etchanol.These patents do not describe the art of pre-swelling polycarbonate orother plastics. A method of increasing adhesion of polyepoxy ispresented in U.S. Pat. No. 3,758,332. The surface of polyepoxy isswollen with solvents such as methylethyl ketone, tetrahydrofuran,dioxane and like. Processes of pre-swelling polyamides with aqueoussolution of organic acids such as trichloracetic acid and otherchlorinated solvents such as dichloropropanol are described in U.S. Pat.Nos. 4,125,649 and 4,335,164. U.S. Pat. No. 4,125,649 also includeformulations containing water miscible halocarbons for pre-swellingfollowed by etching with chromic acid.

A published patent application (PCT Int. Appl. No. 86/US/1199, Jan. 15,1987) to C. Courduvelis and D. E. Stone, describes formulations andprocesses of pre-swelling plastics such as polyether polyimide withsolvents such as dimethylsulfoxide, propanediol ether, followed byetching with chromic acid.

The prior art describes neither (1) etching of polycarbonate in one stepnor (2) etching of polycarbonate in two steps (pre-swelling) followed bydegradation wherein polycarbonate is degraded (etched) with a solutioncontaining a solubilizing agent, and/or a wetting agent and a base.Etching pre-swollen polycarbonate with mineral acids other than chromicacid is also not taught.

SUMMARY OF THE INVENTION

We have found that plastics of functionalized polymers having at leastone hydrolyzable functionalty such as anhydride, ester (carboxyl andsulfonic), amide, urethane and imide, preferably polycarbonate, can beswollen and etched for plating by certain swelling agents anddegradation agents, in one, two or three steps. The etched surfaceprovides satisfactory adhesion of electroless nickel or copper. Ifrequired, a solubilizing agent is used to increase the miscibility ofdegradation and swelling agents. The polymers can be swollen and etchedin one bath by using a mixture of swelling (or wetting agent) anddegradation agents or with a compound having the ability to swell andetch the polymers simultaneously. In the two-step process, swelling anddegradation is done separately. In the three-step process, the plasticsurface is swollen and etched with mineral acids followed by treatmentwith a base.

BRIEF DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS

A water miscible swelling agent is preferred for pre-swellingpolycarbonate. If the swelling agent is not itself miscible with water,or if it does not dissolve the selected basic degradation agent, it canbe made miscible or a solvator by addition of a solublzing agent.

Some representative functional groups which rapidly swell polymers suchas polycarbonate include: Ether (--O--), halocarbon (X-C, where X is ahalogen radical), and aromatic compounds. Certain ketones, acetals andketals can also swell polycarbonate. Aliphatic ethers are the preferredclass of compounds for swelling polycarbonate and other plastics mainlybecause some of them are water soluble and are stable to bases.

The following is a non-limiting list of some representative classes ofcompounds and specific examples of such "good solvents".

Alkyl ethers and substituted alkyl ethers, such as halo- or hydroxy-substituted alkyl ethers including ethers of alkylene glycols,arylethers, arylalkylethers, cyclic ethers and their derivatives.Preferably there are used lower alkyl and lower alkylene moieties of1-20 and 2-20 carbon atoms respectively. As aryl moieties, phenyl,suitably substituted phenyl may be used. Specific examples includesolvents such as propanediol dimethylether, ethoxyacetic acid,methoxyethylether, 2-(2-amino ethoxy)ethanol,1,2-bis(2-chloroethoxy)ethane, 1,4-butanediol diglycidyl ether,2-(2-n-butoxyethoxy)ethanol, 2-(2-chloroethoxy)ethanol,2-[2-(2-chloroethoxy)ethoxy] ethanol, diethylene glycol dibutyl ether,2-(2-ethoxy ethoxy)ethanol, 2-ethoxyethyl ether, ethylene glycoldimethyl ether, diethyleneglycol dimethylether, dipropylene glycoldimethylether, 2-methoxyethylether (diglyme), dimethoxy propane, ethoxyethylether, butylphenylether, 2-(2-methoxyethoxy)ethanol, tetraethyleneglycol dimethyl ether, triethylene glycol dimethyl ether andpolyethylene glycol. Benzyl ether, phenyl ether, benzoxy benzyl alcohol,methoxy benzyl alcohol. Cyclic ethers and their derivatives, such asbenzofuran, butanediol diglycidyl ether, dioxane and substituteddioxanes, trioxanes and substituted trioxanes, furans, furfuryl alcohol,morpholines and substituted morpholines such as dimethylaminoethylmorpholine, ethylmorpholine, 4-morpholineethane sulfonic acid,4-methylmorpholine-N-oxide), tetrahydrofuran and substitutedtetrahydrofurans such as dimethoxy hydrofuran or dimethoxytetrahydrofuran.

Aldehydes, ketones, acetals and ketals derived from lower alkanols andlower alkanoic acids of 1 to 6 carbon atoms or phenyl lower alkanols orlower alkanoic acids. Included in this category are phenylacetaldehyde,glyceraldehyde, benzylacetone, dichloroacetone, methoxyacetone,benzophenone, propionaldehyde diethyl acetal, dioxolane, and trioxanemay also be used.

Water miscible halocarbons which can be used as swelling agents includemono-- and poly--, chloro-- and fluoro--substituted derivatives ofacetone, acetic acid, butanol, ethanol, and propanol. A good solvent canbe made poor by adding a miscible nonsolvent and vice versa.

A compound can be used as solubilizing agent if it is soluble in theswelling agent and a nonsolvent (such as water) selected to convert a"good" swelling agent to a "poor" one. Organic compounds having --OH,--COOH, --SO₃ H, --NH--, --NH₂, --NR₃, --N⁺ R₄ and other polarfunctionalities can act as solublizing agents. For example, ethanol,glycerols, acetic acid, and benzene sulfonic acid can be used assolublizing agents. For example, chloroform and dichloromethane haveability to swell polycarbonate but they are not miscible with water.When methanol is added to an immiscible mixture of chloroform and water,a clear solution is obtained which has ability to swell polycarbonate.

Especially desirable as solubilizing and swelling agents arealkanolamines and phenolamines such as benzyl-N-methylethanolamine,diethylaminophenol, 2-[(2-dimethylamino)ethyl]methyl aminoethanol,ethanolamine, diethanolamine, dimethyethanolamine, butyldi-ethanolamine, triethanolamine, 5-diethylamino-2-pentanol, diethyl-ethanolamine, dialkoxy benzene, dimethylamino propanol,dimethylethanolamine, chloroethoxyethanol, tetra kis(2-hydroxyethyl)ethylenediamine, tripentaerythritol, 2,4,6-tris(dimethylaminomethyl)phenol. Tertiary amines such as pyridine and substituted pyridines forexample dialkylaminopyridines, aniline and substituted anilines, forexample dialkylanilines, hexamethylenetetraamine,tetramethylethylenediamine, tetraethylenepropanediamine. Ether-aminessuch astris(2-methoxyethoxyethyl)amine,benzethonium,4(2-dimethylamino)ethylmorpholine,glycerol, isopropanol, acetic acid, palmitic acid, benzoic acid, benzenesulfonic acid and dimethyl formamide.

The addition of certain compounds, designated as wetting agents maypermit an inactive etchant to become active. Wetting agents areinherently soluble in the inactive solvent. Thus, while they act likesolubilizing agents, they cannot be so designated. Examples of suchwetting agents are triethanolamine and glycerol which activate aqueoussodium hydroxide. For example, aqueous NaOH does not etch swollenpolycarbonate very effectively, even at high concentration andtemperature. However, an aqueous solution of triethanolamine calciumsolubilizing agent which also acts as wetting agent in this case allowsNaOH to etch swollen polycarbonate very effectively at room temperatureand at lower concentration of NaOH.

It is quite likely that some swelling agents may form an emulsion. Suchemulsions can be destroyed to form a clear solution for pre-swellingpolycarbonate by adding a solubilizing and/or a wetting agent agent.

Thus, swelling agents which are normally insoluble in water can be usedfor pre-swelling polycarbonate and other plastics by using appropriatesolublizing agents. Thus the choice for selection of swelling agents forplastic is widened.

There is no sharp line of demarcation between swelling agents, wettingagents and solubilizing agents. A solubilizing agent can also be aswelling agent and vice-versa. For example, triethyleneglycoldimethylether is a good swelling agent. It can also be used as asolubilizing or wetting agent. agent.

Certain compounds may be used ether as solubilizing agents or as poorsolvents (useful swelling agents), for example: 2-butoxyethanol,2-(2-butoxy ethoxy)ethanol, diethyleneglycol, monoethers of ethyleneglycols, propylglycols, and glycerol,ethoxyethanol,2(2-ethoxyethoxy)ethanol,ethers oftetraethyleneglycol,benzethonium and tetrabutylphosphoniumbromide.

Nonsolvents which convert "good" solvents to "poor" solvents, may or maynot require the use of a solubilizing agent. In addition to water, thereinclude mono- and polyhydric alcohols which, preferably do not carryhalo or ether functions. Other suitable nonsolvents include alkanols andglycols of 1-20 carbon atoms.

As nonsolvents, there may be specifically recited: inorganic nonsolventssuch as water and phosphoric acid. Organic nonsolvents such ashydrocarbons, suitably alkanes and phenyl alkanes of 6 to 20 carbonatoms such as: decane, toluene, xylene, etc.; alkanoic acids, suitablyacetic acid, decanoic acid, citric acid, etc.; alcohols suitably lowermono and polyhydric alkanols including sugars and phenols, these areexemplified by ethanol, isopropanol, glycerol, glucose, phenol, etc.;high molecular weight amides of more than 6 carbon atoms such asoctadecanamide; high molecular weight amines such as dodecyleamine; highmolecular weight ketones, such as butanone, octanone; and high molecularweight esters, such as butyl acetate, dimethyloxylate. Some of thenonsolvents such as triethanolamine, can also be solubilizing agents orwetting agents.

The invention is not limited to swelling agents which are liquid at roomtemperature. A compound which is solid at room temperature but eithercan be dissolved in water or other solvents can also be used as swellingagent. A compound which has low melting point, e.g. below 150° C. canalso be used in the present invention. The swelling bath can be preparedby melting the compound and maintaining the bath above the meltingtemperature.

Certain compounds have the ability to swell polycarbonate and also haveacid or base functionality. Thus, they can simultaneously act asswelling agents as well as degradation agents. These groups of compoundsshould have at least one or more of the following functionalities forswelling polymer and degradation of carbonate functionality:

Compounds having functional groups such as --SO₃ H, and --N^(+R) ₄ OHcan cause degradation of polycarbonate. Under suitable conditions, e.g.,with appropriate swelling agent and high temperature, polycarbonate canalso be degraded by primar (R-NH₂), secondary amines (R-NH-R), tertiaryamines(NR₃) and carboxylic acids (R-COOH) wherein R is alkyl, aralkyl oraryl. Aryl sulfonic acids which can be mono-, ortho-, meta- andpara-substituted di; and tri- substituted benzene sulfonic acids, andnaphthalene sulfonic acids are especially suitable. Compounds havingether and N⁺ -OH functionality can also swell and etch PC, such as tris(2-methoxy ethoxyethyl)ethyl ammonium hydroxide are especially suitable.

For example, molten benzene sulfonic acid acts as a solvent to swellpolycarbonate. The sulfonic acid group has ability to hydrolyze thecarbonate functionality thereby degrading polycarbonate. The surface ofpolycarbonate becomes wettable and provides acceptable adhesion ofelectroless nickel, after immersion in molten benzene sulfonic acid.

Benzene sulfonic acid diluted with inorganic liquids such as water,sulfuric acid and phosphoric acid or diluted with organic liquids suchas ethers are essentially unaffected by benezene sulfonic acid, can beused as pre-etching systems. The pre-etching can be controlled bydiluting benzene sulfonic acid. Preferred diluents are water and aqueoussulfuric acid.

After pre-etching with the benezene sulfonic acid, polycarbonate can beetched with an inorganic or organic base such as sodium hydroxide ortetraethylammonium hydroxide. As shown, polycarbonate plaques pre-etchedwith benezene sulfonic acid followed by etching sodium hydroxide can besatisfactorily plated with electroless nickel.

Representative examples of quaternary ammonium compounds which can beused as degradation agents alone or with alkali metal hydroxides areAliquot, benzalkonium chloride, benzylcetyldimethylammonium chloride,benzyltriethyl ammonium chloride, benzyltrimethylammonium chloride,benzyltrimethylammonium hydroxide, cetyldimethylethylammonium bromide,cetyltrimethylammonium bromide, choline chloride, choline hydroxide,tetraethylammonium bromide, tetraethyl ammonium hydroxide,benzyltriethylammonium chloride, and benzyltrimethyl ammonium hydroxide,betaine, decamethylenebis(trimethylammonium iodide),cetyltrimethylammonium bromide, hexamethonium bromide, methyltributylammoniumchloride, phenyltrimethylammoniumchloride,benzyltributylammonium chloride, benzyltrimethylammonium chloride,benzethonium, benzyldimethyl sterylammonium chloride andbenzylcetyldimethyl ammonium chloride.

Preferred degradation agents include quaternary ammonium hydroxides suchas tetraethylammonium hydroxide and choline hydroxide. A mixture ofquaternary ammonium salts such as tetraethylammonium chloride and/orcholine chloride and alkali metal hydroxide such as KOH are alsodesirable degradation agents.

The most preferred degradation agents are alkali metal hydroxide.However, aqueous solutions of alkali metal hydroxides are not veryeffective in etching polycarbonate, unless solvated with a solubilizingagent and/or wetting agent.

For the one-step process the swelling agent must be stable to the baseused for degradation of polycarbonate. However, stability to a base isnot required for the two- and three-step etching process. In the lattercases, compounds such as inorganic and organic esters, for example,ethylacetate, glycol acetate, propylene glycol acetate, cellusolveacetate, and like can be used for pre-swelling.

While the one-step swelling/etching process is especially preferred, thetwo-step process for swelling, followed by etching of polycarbonate, isalso equally desirable.

The one-step swelling/etching solutions can also be used as etchantsolution in two-step etching process. In such case, better adhesion ofelectroless metal is expected because the plastic is already pre-swollenand hence etching could be faster and smoother. For better control ofthe etching process, one may reduce the concentration of the swellingagent in the etching solution. There is no sharp line of demarcationbetween the swelling/etching solution of one-step process and theetching solution of the two-step process.

Though pre-etching and etching are preferred to be carried out at roomtemperature, higher and lower temperatures can be used. If the reactionis fast at RT, lower temperature can be employed and vice versa.

The swelling and etching formulations and processes described here arenot limited to polycarbonate. They can be used for a number of otherplastics having at least one hydrolyzable functionalities such asanhydride, ester (carboxyl and sulfonic), amide, urethane and immide.(The polymer could be a copolymer and/or an alloy of two or morepolymers).

EXAMPLES

The following examples are illustrative of carrying out the claimedinvention but should not be construed as being limitation on the scopeor spirit of the instant invention.

Hereinbelow, unless stated to the contrary, all ratios and percentagesare v/v.

EXAMPLE 1 Plating baths/line

After preswelling and/or etching the polycarbonate parts with theformulations and processes described in Examples 15 to 40, they wereplated with electroless copper or nickel using the formulations andprocesses described below:

1a--Catalyst

120 ml. of 12N HCl was mixed with 880 ml. of deionized water. To thisacid solution was added 40 ml. of Enplate 443 solution (supplied byEnthone INC., New Haven, Conn.) to make the catalyst bath. Etched partswere rinsed with water and immersed in the catalyst bath for 4-8minutes, usually 6 minutes, at room temperature. The parts were rinsedwith water before immersing in the accelerator bath.

1b--Accelerator

100 ml. of Enplate Accelerator 860 (Supplied by Enthone, Inc.) was mixedwith 900 ml. of deonized water to make the accelerator bath. Thecatalyzed parts were immersed in the accelerator bath for 8-15 minutes,usually 10 minutes, at room temperature. After rinsing the parts withwater, they were immersed in either electroless nickel or electrolesscopper baths described below:

1c--Electroless Nickel

To 898 ml. of deionized water 47 ml. of Enplate Ni 880A (supplied byEnthone Inc.) was added. To the mixture, 55 ml. of Enplate Ni 880Bsolution (supplied by Enthone, Inc.) was added. The pH of the bath wasadjusted to 9 with ammonium hydroxide. The plastic parts were immersedin this bath for 8 to 20 minutes at room temperature.

1d--Electroless Copper

To 560 ml. of deionized water, 80 ml. of Enplate Cu-404A and 160 ml ofEnplate Cu-404B (both supplied by Enthone, Inc.) were added. The plasticparts were immersed in this bath for 8 to 120 minutes at roomtemperature.

EXAMPLE 2 Test methods

Pre-etched, etched and plated polycarbonate parts were tested using thefollowing methods:

2a--Pre-etch test

The pre-etch usually swells plastic and hence the smooth surface of theplastic becomes rough and deglazed. The degree of swelling was estimatedqualitatively as follows:

Excessive Swelling: Very rough surface. Transparent sheets becomeessentially opaque.

Proper Swelling: Moderately micro-roughened surface. Transparent sheetsbecome translucent.

Poor Swelling: Smooth surface. Surface remains essentially unaffected.Transparent sheets remain transparent.

2b--Etching test

Surface wettable with water. A thin layer of water remains on the etchedsurface.

2c--Adhesion of Electroless metals

Adhesion of electroless nickel and copper was tested using thecross-hatch and thermal cycle tests.

Cross-Hatch test: The plated metal coat was cut crosswise with across-cut tool (Precision Gage & Tool Company, Dayton, Ohio) using theprocedure described in ASTM method #D3359. One end of Scotch(cellophane) tape was firmly applied on the cross-hatch. The tape waspulled from the other end. The adhesion was rated as below:

Satisfactory: A few cross hatched pieces peel (flake) off. If properexperimental conditions of pre-etching, etching and plating are used,the satisfactory plating can become good or excellent plating.

Acceptable: No flaking off of cross-hatched pieces, but some peeling ofmetal occurs at crosscuts. If proper experimental conditions ofpre-etching, etching and plating are used, the acceptable plating canbecome good or excellent plating.

Good: No flaking off of any kind.

Excellent: No flaking even after thermal cycle.

Thermal cycling: Polycarbonate parts were placed in steam autoclave for20 minutes at 110° C. and 12 psi pressure. The parts are then cooled toroom temperature. If the adhesion of plated metals is good or excellent,the plated metal does not blister or plate separation does not occur.

EXAMPLE 3 Effect of an Ether (good solvent or good swelling agent) onpolycarbonate

Polymer: Transparent polycarbonate (Laxan) sheet

Solution: Triethylene glycol dimethylether

Results: The sheet becomes opaque in 30 seconds. Nonwettable surface,indicative of unetched surface.

EXAMPLE 4 Reducing the Surface Roughening on Polycarbonate by addingNonsolvent (nonswelling agent)

Polymer: Transparent polycarbonate (Laxan) sheet

Solution: Triethylene glycol dimethylether: water (8:2)

Results: The surface gets roughened in 10 minutes. Nonwettable surface.

EXAMPLE 5 Effect of Polyether (poor solvent) on Polycarbonate

Polymer: Transparent polycarbonate (Laxan) sheet

Solution: Polyethyleneglycol methylether, molecular weight=350.

Results: Damages (deglazes) the surface in 5 minutes at roomtemperature. Nonwettable surface.

EXAMPLE 6 Effect of addition of Nonsolvent in Poor Solvent

Polymer: Transparent polycarbonate (Laxan) sheet

Solution: Polyethyleneglycol methylether (molecular weight=350): water(7:2)

Results: No noticeable damage at RT for 5 minutes.

EXAMPLE 7 Effect of Nonsolvent

Polymer: Transparent polycarbonate (Laxan) sheet

Solution: Polyethyleneglycol (mol.wt.=200)

Results: No noticeable damage at RT for 30 minutes.

EXAMPLE 8 Comparison between good, poor and nonsolvent

Polymer: Transparent polycarbonate (Laxan) sheet

    ______________________________________                                                   Time (min.)                                                                              Clarity                                                 Liquid     of immersion      Swellability                                     ______________________________________                                        EGDME      1          Opaque     Good                                         EGDME:Water                                                                              2          Translucent                                                                              Poor                                         (8.2)                                                                         EG:DME:Water                                                                             5          Transparent                                                                              Bad                                          (5.5)                                                                         EE         30         Transparent                                                                              Bad                                          EG         30         Transparent                                                                              None                                         ______________________________________                                         EGDME = Ethylene glycol dimethylether,                                        EE = Ethoxy ethanol.                                                          EG = Ethylene glycol, Temperature was room temperature.                  

EXAMPLE 9 Effect of Mixture of Good Solvent, Solubilizing Agent andOrganic Base

Polymer: Polycarbonate (Laxan) plaque

Solution: Triethylene glycoldimethylether:isopropanol:tetraethylammonium hydroxide 25% solution(2:1:1) at room temperature for 5 minutes.

Results: Roughens the surface and surface is wettable.

EXAMPLE 10 Effect of Temperature on Pre-etch Treatment

Polymer: Polycarbonate (Laxan) plaque

Solution: As in Example 9 but at 60° C.

(Triethylene glycol dimethylether:isopropanol:tetraethylammoniumhydroxide 25% solution (2:1:1) at 60° C. for 5 minutes).

Results: Highly roughened and wettable surface.

EXAMPLE 11 Solubilizing a Swelling Agent

Polymer: Polycarbonate

Solution: 40 ml. of chloroform and 10 ml. of water

Result: An immiscible mixture

Solubilizing agent: 50 ml. of methanol added to above solution.

Results: The immiscible mixture forms a clear solution upon addition ofmethanol (solubilizing agent). This solution swells polycarbonate.

EXAMPLE 12 Solubilizing a Mixture of Swelling and Degradation Agents

Polymer: Polycarbonate (Laxan) plaque

Solution: 10 ml. of 10% aqueous solution of NaOH plus 2.5 ml. ofShipley's pre-conditioner (PM-921 Conditioner) which contains of waterand dichloropropanol.

Results: Two layers are formed.

Solubilizing agent: 5 ml. of polyethylene glycol (mol. wt.=200) added tothe above mixture.

Results: A clear single phase solution is obtained.

(NOTE: A mixture of alkali and halogenated solvent is not desirable inpractice).

EXAMPLE 13 Solubilizing a Mixture of Degradation Agent and SwellingAgent

Polymer: Polycarbonate (Laxan) plaque

Solution: 10 ml. of 10% NaOH and 2.5 ml. triethylene glycol dimethylether.

Results: Two layers are formed.

Solubilizing agent: 2 ml. of polyethylene glycol (mol. wt.=200) added tothe above mixture.

Results: A clear single phase solution is obtained. This mixture swellsand etches polycarbonate. The etched surface is wettable.

EXAMPLE 14 Effect of Mild Swelling Solution containing Inorganic Base

Polymer: Polycarbonate (Laxan) plaque

Solution: Polyethylene glycol methyl ether (molecular weight=350):water: 10% NaOH (7:2:1)

Results: Polymer swells and etches in 5 minutes at RT.

EXAMPLE 15 Etching with Aqueous KOH Solution

Polymer: Polycarbonate (Laxan) plaque.

Pre-treatment: None.

Etch Formulation: 6N Aqueous solution of KOH 20 minutes, at RT

Electroless Nickel: As described in Example 1

Results: The surface remains unaffected. Nonwettable surface. Very pooradhesion of electroless nickel.

EXAMPLE 16 Etching with Alcoholic KOH Solution

Polymer: Polycarbonate (Laxan) plaque.

Pre-treatment: None.

Etch Formulation: 1:1 aqueous KOH: isopropanol, 20 minutes, at RT

Electroless Nickel: As described in Example 1

Results: The surface remains unaffected. Nonwettable surface. Pooradhesion of electroless nickel.

EXAMPLE 17 Etching with Alcoholic Tetraethyl Ammonium Hydroxide Solution

Polymer: Polycarbonate (Laxan) plaque.

Pre-treatment: None.

Etch Formulation: 10% solution of tetraethyl ammonium hydroxide inethanol:water (90:10), 20 minutes, at RT

Electroless Nickel: As described in Example 1.

Results: The surface remains unaffected. Nonwettable surface. Pooradhesion of electroless nickel.

EXAMPLE 18 Etching with Aqueous Solution of Tetraethyl Ammoniumhydroxide

Polymer: Polycarbonate (Laxan) plaque.

Pre-treatment: None.

Etch Formulation: 20% aqueous solution of tetraethyl ammonium hydroxide20 minutes, at RT.

Electroless Nickel: As described in Example 1.

Results: The surface remains unaffected. Nonwettable Surface. Pooradhesion of electroless nickel.

EXAMPLE 19 Plating of Polycarbonate parts without Pre-etch treatment butEtched with Acids

Polymer: Polycarbonate (Laxan) plaque.

Pre-treatment: None.

Etch Formulation: Sulfuric (50 ml.) plus phosphoric (50 ml.) plus 1 ml.nitric (other ranges are: sulfuric 30-80%, phosphoric 0-50%, nitric 0.1to 10%, and water-Balance).

Time: 5 and 10 minutes at RT.

Comments: The etched surface was not very wettable.

Electroless Nickel: As described in Example 1.

Results: Poor adhesion of electroless nickel

EXAMPLE 20 Pre-etch with Ether Solution followed by Etching with Acids(2 stage)

Polymer: Polycarbonate (Laxan)

Pre-etch: Enplate 3489: Water (75:25 v/v) (made from an ether)

Temperature: 75° C. (Temperature range: 25°-85° C.)

Time: 7 minutes (Time range tried: 3-10 minutes)

Etch Formulation: Sulfuric (50 ml.) plus phosphoric (50 ml.) plus 1 ml.nitric (other ranges are: sulfuric 30-80%, phosphoric 0-50%, nitric 0.1to 10%, and water-Balance).

Time: 10 minutes (Other ranges: 3-30 minutes)

Temperature: RT (Other ranges: 25° to 85° C.)

Electroless Nickel: As in Example 1.

Results: Adhesion of electroless nickel: Passes the cross-hatch test andimproves upon storage at RT or upon annealing at higher temperatures,e.g., 80° C. for one hour.

Comments: Plated samples need annealing to improve the adhesion ofelectroless nickel.

EXAMPLE 21 Pre-Etch with Ether Solution followed by Etching with Acids(2 Stage)

Polymer: Polycarbonate (Laxan) plaque

Pre-etch Formulation: Enplate 3489: Water (75:25 v/v), 7 minutes, at RT

Etch Formulation: Sulfuric (55 ml.), and phosphoric (45 ml.), 10 minutesat RT

Electroless Nickel: As in Example 1.

Results: Excellent adhesion of electroless nickel. Passes thermal cycletest.

EXAMPLE 22 Pre-Etch with Halocarbon Solution followed by Etching withAcids (2 Stage)

Polymer: Polycarbonate (Laxan) plaque

Pre-etch Formulation: Shipley PM 921 (prepared from dichloro propanol):Water (80:120 v/v,) 5 minutes at 45° C.

Etch #1 Formulation: Sulfuric (55 ml.), and phosphoric (45 ml.) 10minutes at RT

Etch #2 Formulation: 10% NaOH 10 minutes at 60° C.

Electroless Nickel: As in Example 1.

Results: Excellent adhesion of electroless nickel.

EXAMPLE 23 Plating of Polycarbonate parts without Pre-etch Treatment butEtched with a Organic Base

Polymer: Polycarbonate (Laxan) plaque

Pre-etch Formulation: None

Etch Formulation: 20% Tetraethylammonium hydroxide in water 5 minutes atRT

Electroless Nickel: As in Example 1.

Results: Polymer is essentially unaffected by this etch. Adhesion ofelectroless nickel and electroless copper is poor.

EXAMPLE 24 Pre-Etching with Halocarbon Solution followed by Etching withOrganic Base (2 stage)

Polymer: Polycarbonate (Laxan) plaque

Pre-etch Formulation: Shipley PM 921: water (80:120), 10 minutes at 45°C.

Etch Formulation: 25 ml of 20% Tetraethylammonium hydroxide in water.

10 minutes at 45° C.

Electroless copper: As in Example 1.

Results: Polymer surface wettable with excellent finish & adhesion ofelectroless copper. Passes thermal cycle test.

EXAMPLE 25 Pre-etching with Halocarbon Solution followed by Etching withOrganic Base containing a Co-solvent (2 stage)

Polymer: Polycarbonate (Laxan) plaque

Pre-etch Formulation: Shipley PM 921: water (2:3), 10 minutes at 45° C.

Etch Formulation: 25 ml. of 20% Tetraethylammonium hydroxide in waterand 10 ml. of isopropanol, 10 minutes at 45° C.

Electroless Copper: As in Example 1.

Results: Polymer surface wettable with excellent adhesion of electrolesscopper. Passes thermal cycle test.

EXAMPLE 26 Effect of Mixture of Solvent, Poor Solvent and Organic Baseon Polycarbonate and its Platability (one-step etching system)

Polymer: Polycarbonate (Laxan) plaque

Swelling/Etching Solution: Triethyelene glycol dimethylether:polyethyelene glycol (mol.wt. 200):tetraethylammonium hydroxide25% solution (1:1:1) at 25° C. for 5 minutes.

Electroless Nickel: As described in Example 1.

Results: Wettable after 2 minute wash with hot water. Acceptableelectroless nickel plating.

EXAMPLE 27 One-step Etching System (without solubilizing agent).

Polymer: Polycarbonate (Laxan) plaque

Swelling/Solution: Triethyelene glycoldimethylether:water:tetraethylammonium hydroxide 25% solution (8:1:1)plus two drops of Aliquot at 35° C. for 5 minutes.

Electroless Nickel: As described in Example 1.

Results: Good adhesion as electroless nickel.

EXAMPLE 28 One-step Etching System (without solubilizing agent)

Polymer: Polycarbonate (Laxan) plaque

Solution: Triethylene glycol dimethylether:water: tetraethylammoniumhydroxide 25% solution (8:2:3) plus two drops of Aliquot at 40° C. for 5minutes.

Electroless Nickel: As described in Example 1.

Results: Wettable surface and excellent adhesion of electroless nickel.

EXAMPLE 29 Two-step Etching System (etch with organic base)

Polymer: Polycarbonate (Laxan) plaque

Step 1: Shipley pre-etch. 6 minutes at 45° C.

Step 2: 20% tetraethylammonium hydroxide in water at 60° C. for 5minutes.

Electroless copper: As described in Example 1.

Results: Good adhesion of electroless copper.

EXAMPLE 30 Two-step Etching System (etch with organic base)

Polymer: Polycarbonate (Laxan) plaque

Step 1: Shipley pre-etch. 6 minutes at 45° C.

Step 2: 20% choline hydroxide in water at 60° C. for 5 minutes.

Electroless copper: As described in Example 1.

Results: Good adhesion of electroless copper.

EXAMPLE 31 Two-step Etching System (etch with alkyl ammonium halide plusinorganic base)

Polymer: Polycarbonate (Laxan) plaque

Step 1: Shipley pre-etch. 6 minutes at 45° C.

Step 2: 15% tetraethylammonium bromide+15% sodium hydroxide in water at60° C. for 5 minutes.

Electroless copper: As described in Example 1.

Results: Good adhesion of electroless copper.

EXAMPLE 32 Two-step Etching System (etch with alkyl ammonium halide plusinorganic base)

Polymer: Polycarbonate (Laxan) plaque

Step 1: Shipley pre-etch. 6 minutes at 45° C.

Step 2: 15% Choline chloride+15% sodium hydroxide in water at 60° C. for5 minutes.

Electroless copper: As described in Example 1.

Results: Good adhesion of electroless copper.

EXAMPLE 33 One step Etching System (with solubilizing agent)

Polymer: Polycarbonate (Laxan) plaque

Pre-etch: None

Swell/Etch: 20 ml Enthone pre-etch 3489+6 ml tetraethylammoniumhydroxide (20% solution in water)+5 ml. isopropanol at 60° C. for 5minutes.

Electroless copper: As described in Example 1.

Results: Good adhesion of electroless copper.

EXAMPLE 34 Use of Solution of one-step Etchant in two-step Etching

Polymer: Polycarbonate (Laxan) plaque

Step 1: 8:2 triethyleneglycol dimethylether: water, 5 minutes at RT

Step 2: 10:2.5:2 Aqueous 10% NaOH : Triethylene glycol dimethyl ether:polyethylene glycol (mol.wt. 200), 5 minutes at RT

Electroless Nickel: As described in Example 1.

Results: Good adhesion of electroless nickel.

EXAMPLE 35 Aromatic Compounds as a Pre-etch System and treatment with abase

Polymer: Polycarbonate (Laxan) plaque

Pre-etching System: Benzene sulfonic acid at 65° C.

Time: 2 minutes: Highly wettable surface-

0.5 minute: Highly deglazed wettable surface.

Etching System: 10% KOH aqueous solution 10 minutes at 50° C.

Results: Benzene sulfonic acid provides wettable surface. The wettablesurface can be plated with electroless nickel and copper with goodadhesion.

EXAMPLE 36 Aromatic Compounds alone as an Etch System

Polymer: Polycarbonate plaque

Swelling/etching System: Molten benzene sulfonic acid at 65° C.

Time: 2 minutes: Highly wettable surface

0.5 minute: Highly deglazed wettable surface.

Results: Benzene sulfonic acid provides wettable surface. The wettablesurface can be plated with electroless nickel and copper.

EXAMPLE 37 Effect of triethanolamine on polycarbonate

Polymer: Transparent polycarbonate (Laxan) sheet

Solution: Triethanolamine at 60° C.

Results: No effect.

EXAMPLE 38 Effect of mixture of triethanolamine and NaOH onpolycarbonate

Polymer: Transparent polycarbonate (Laxan) sheet

Solution: 50 ml 25% NaOH+25 ml triethanolamine, 10 minutes at 60° C.

Results: No effect.

EXAMPLE 39 Two-step etching system using triethanolamine (wetting agent)

Polymer: Polycarbonate (Laxan) plaque

Step 1: Enthone pre-etch 3489, 10 minutes at 45° C.

Step 2: 50 ml 25% NaOH+25 ml triethanolamine, 5 minutes at RT

Electroless nickel: As described in Example 1

Results: Good.

EXAMPLE 40 One-step etching system using triethanolamine as solubilizingagent/wetting agent

Polymer: Polycarbonate (Laxan) plaque

Etching Solution: Triethanolamine: Triethyelene glycol

dimethylether: NaOH: water (2.5:4:1.5:10 v/v/w/v) at 50° C. for 5minutes.

Electroless Nickel: As described in example 1

Results: White nickel. Good adhesion.

EXAMPLE 41 Optimized testing

Polymer: Polycarbonate (Laxan FL-900 and 920A) panels

Pre-etching: Pre-etch with Enplate 3489: water (75:25)

Temperature: 75° F.,

Time: 10 minutes for FL-900 and 5 minutes for 920A

Rinses: (cold, hot and cold water rinses)

Etching: The formulations containing (1) Triethanolamine, TEA (variedfrom 30-80%), (2) Sodium hydroxide (0.5-1.5N), and (3) Water (balance)were used.

Temperature: 150°-170° F.

Time: 10 minutes

Rinse: Cold, hot and cold water rinses

Electroless Plating:

(1) Pre-catalyst: Enplate 3923, 75° F., 2 min, cold water rinse (CWR)

(2) Catalyst: Enplate 850, 75° F., 5 min, CWR

(3) Accelerator: Enplate 860, 75° F., 5 min, CWR

(4) Electroless copper: Enplate 872, 75° F., 20 min, CWR

(5) Surface activation: Enplate 452, 75° F., 1 min, CWR

(6) Electroless nickel: Enplate 426, 150° F., 5 min, CWR

(7) Annealed at 170° F. for 30 min

Results: Plated samples were autoclaved five times at 12-15 psi for 30minutes and then tested for adhesion with the ASTM cross-hatch testmethod between each autoclave. The results are summarized below (1poor-5 excellent) after five cycles:

    ______________________________________                                                     Initial       After autoclave                                    Concentration                                                                              Conc. (N) of NaOH                                                                           Conc. (N) of NaOH                                  of TEA       0.5    1.0     1.5  0.5   1.0 1.5                                ______________________________________                                        (A) Polycarbonate Laxan 920A panels etched at 170° F.                  30           2      5       5    1     2   2                                  40           2      5       5    1     2   2                                  50           4      5       5    3     5   5                                  60           5      5       5    4     5   5                                  70           5      5       5    5     5   5                                  80           5      5       5    5     5   --                                 (B) Polycarbonate Laxan FL-900 panels etched at 170° F.                30           2      5       5    1     4   5                                  40           3      5       5    2     3   4                                  50           5      5       5    4     5   4                                  60           --     5       5    --    3   5                                  70           5      5       5    4     5   5                                  80           5      5       5    4     4   --                                 (C) Polycarbonate Laxan 920A panels etched at 150° F.                  30           3      5       5    2     4   3                                  40           2      5       5    1     5   5                                  50           3      5       5    2     5   5                                  60           4      5       5    5     5   5                                  70           5      5       5    5     5   5                                  80           5      5       5    5     5   5                                  (D) Polycarbonate Laxan FL-900 panels at 150° F.                       30           3      5       5    1     4   5                                  40           4      5       5    1     3   5                                  50           5      5       5    2     4   5                                  60           5      5       5    2     5   5                                  70           5      5       4    5     5   5                                  80           5      5       5    5     5   5                                  ______________________________________                                    

EXAMPLE 42 One-step etching system using low organic content

Polymer: Polycarbonate (Laxan) plaque

Etching Solution: Water:NaOH:Triethanolamine:Ethyleneglycoldimethylether (120:15:28:37 w:w:w:w) at 50° C. for 10 minutes

Electroless Nickel: As described in Example 1

Results: Good adhesion.

EXAMPLE 43 Effect of tris(2-methoxyethoxy)ethylamine on PC

Polymer: Transparent polycarbonate (Laxan) sheet

Solution: Triethanolamine at RT

Results: Deglazes PC in 30 seconds

EXAMPLE 44 Effect of tris(2-methoxyethoxy)ethylamine (TMEA) onpolycarbonate

Polymer: Transparent polycarbonate (Laxan) sheet

Solution: TMEA: Triethanolamine: tetraethylammonium hydroxide (25%):water (6:3:2.5:2) at RT for 5 minutes at 50° C.

Electroless Nickel: As described in Example 1

Results: Good adhesion.

EXAMPLE 45 Etching and Plating of Polystyrene

Polymer: Polystyrene plaque

Solution: 10% aqueous NaOH, Triethylene glycol dimethylether:polyethylene glycol (20:5:4), 10 minutes at 60° C.

Electroless Nickel: As described in Example 1.

Results: Extremely poor adhesion of electroless nickel.

EXAMPLE 46 Etching and Plating of CR-39 (an aliphatic crosslinkedpolycarbonate)

Polymer: CR-39 plaque

Solution: 10% aqueous NaOH, Triethylene glycol dimethylether:polyethylene glycol (20:5:4), 10 minutes at 60° C.

Electroless Nickel: As described in Example 1.

Results: Almost satisfactory adhesion of electroless nickel.

EXAMPLE 47 Etching and Plating of Polyester (polyethylene terephthalate)

Polymer: Mylar (duPont)

Solution: 10% aqueous NaOH, Triethylene glycol dimethylether:polyethylene glycol (20:5:4), 10 minutes at 60° C.

Electroless Nickel: As described in Example 1.

Results: Satisfactory adhesion of electroless nickel

Comment: Satisfactory adhesion of electroless nickel was obtained withanother polyester, Dexloy-347.

EXAMPLE 48 Etching and Plating of Polyamide (Nylon 6)

Polymer: Mineral filled Nylon 6

Solution: 10% aqueous NaOH, Triethylene glycol dimethylether:polyethylene glycol (20:5:4), 10 minutes at 60° C.

Electroless Nickel: As described in Example 1.

Results: Satisfactory adhesion of electroless nickel.

EXAMPLE 49 Etching and Plating of a Polymer Alloy

Polymer: Dow Pulse (an alloy of ABS and polycarbonate)

Solution: 10% aqueous NaOH, Triethylene glycol dimethylether:polyethylene glycol (20:5:4), 10 minutes at 60° C.

Electroless Nickel: As described in Example 1.

Results: Satisfactory adhesion of electroless nickel.

We claim:
 1. A process of single step surface etching of polymericmaterials made of polymers having at least one hydrolyzablefunctionality, selected from the group consisting of polycarbonate,polyanhydrides, polycarboxyl esters, polysulfonic esters, polyamides andpolyurethanes which comprises the step of exposing the surface to beetched to a liquid phase simultaneously capable of microroughening andhydrolysing the said functionalities on said surface to the extentneeded to provide a water wettable surface capable of being plated withelectroless nickel or electroless copper to provide a plated layerhaving a satisfactory level of adhesion to said surface wherein saidliquid phase comprises a good solvent for said polymers and asubstantial non-solvent for said polymers and an effective amount of anetchant therefore selected from the group consisting of alkali metalhydroxides, quaternary ammonium hydroxides and mixtures thereof,provided that where at least one member of the group of said good, saidnon-solvents and said etchant is immiscible with at least one othermember of the group, said liquid phase further comprises a sufficientamount of solubilizing agent miscible with said immiscible components toprovide a single liquid phase.
 2. A process of claim 1 wherein thehydrolyzable functionalities are selected from the group consisting ofcarbonate, anhydrides, carboxyl esters, sulfonic esters, amides orurethanes and said polymers are derived from a single monomer, arecopolymers, or alloys of two or more copolymers.
 3. A process of claim 1wherein said good and said non solvents are immiscible and said liquidphase further comprises a sufficient amount of a solubilizing agentmiscible with said good and said non solvents to provide a single liquidphase.
 4. A process of claim 1 wherein at least one member of the groupof said good, said non solvents and said etchant is immiscible with atleast one other member of the group, said liquid phase further comprisesa sufficient amount of a solubilizing agent miscible with saidimmiscible components to provide a single liquid phase.
 5. A process ofclaim 1 wherein the non-solvent is selected from the group consisting ofwater, lower alkylene glycols and lower alkanols.
 6. A process of claim1 wherein the solubilizing agent is selected from the group consistingof lower alkanoic acids, lower alkylene glycols, lower alkanols andbenzene sulphonic acid.
 7. A process of claim 1 wherein the good solventis selected from the group consisting of mono- or di- lower alkyl ethersof mono-, di- or tri-lower alkylene glycols.
 8. A process of claim 7wherein the good solvent is selected from the group consisting of mono-or di- methyl or ethyl ethers of mono-, di- or tri-ethylene glycol.
 9. Aprocess of claim 1 wherein the polymer is a polycarbonate.
 10. A processof claim 1 wherein the liquid phase is molten benzene sulphonic acid.11. A process of claim 1 wherein the liquid phase comprises an aqueousmicroroughening and hydrolysing agent and a wetting agent for saidpolymers miscible with said liquid aqueous phase.
 12. A process of claim11 wherein the liquid phase comprises aqueous alkali.
 13. A process ofclaim 11 wherein the wetting agent is triethanolamine.